# How do you complete the square to solve 2x^2 + 9x + 4 = 0?

May 31, 2015

a=2 b=9 c=4

Delta=b²-4ac
Delta=9²-4*2*4
$\Delta = 81 - 32$
$\Delta = 49$ ( =7² )

${x}_{1} = \frac{- b - \sqrt{\Delta}}{2 a}$

${x}_{1} = \frac{- 9 - 7}{4}$

${x}_{1} = - \frac{16}{4}$

${x}_{1} = - 4$

${x}_{2} = \frac{- b + \sqrt{\Delta}}{2 a}$

${x}_{2} = \frac{- 9 + 7}{4}$

${x}_{2} = - \frac{2}{4}$

${x}_{2} = - \frac{1}{2}$